Linear Multi-Domain Electrocardiogram

ABSTRACT

Systems and methods are provided to detect a multi-domain ECG waveform. Electrical impulses are detected between at least one pair of electrodes of two or more electrodes placed proximate to a beating heart and are converted to an ECG waveform for each heartbeat of the beating heart. The ECG waveform for at least one heartbeat is received from the detector, the ECG waveform is converted to a frequency domain waveform, the frequency domain waveform is separated into two or more different frequency domain waveforms using two or more different bandpass filters, and the two or more different frequency domain waveforms are converted into two or more different time domain waveforms. The two or more different time domain waveforms are displayed in the same time domain plot as a multi-domain ECG waveform for the at least one heartbeat.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation in part of U.S. patent applicationSer. No. 14/662,996, filed Mar. 19, 2015, which is a continuation of PCTApplication No. PCT/US15/20828, filed Mar. 16, 2015, which claims thebenefit of U.S. Provisional Patent Application Ser. No. 62/008,435,filed Jun. 5, 2014, and this application claims the benefit of U.S.Provisional Patent Application Ser. No. 62/017,185, filed Jun. 25, 2014,the content of all of which is incorporated by reference herein in theirentireties.

INTRODUCTION

Electrical signals produced by a human heart were observed throughelectrodes attached to a patient's skin as early as 1879. Between 1897and 1911 various methods were used to detect these electrical signalsand record a heartbeat in real-time. In 1924, Willem Einthoven wasawarded the Nobel Prize in medicine for identifying the variouswaveforms of a heartbeat and assigning the letters P, Q, R, S, T, U, andJ to these waveforms. Since the early 1900s the equipment used forelectrocardiography (ECG or EKG) has changed. However, the basicwaveforms detected and analyzed have not changed.

An ECG device detects electrical impulses or changes in the electricalpotential between two electrodes attached to the skin of a patient asthe heart muscle contracts or beats. Electrically, the contraction ofthe heart is caused by depolarization and repolarization of variousparts of the heart muscle. Initially, or at rest, the muscle cells ofthe heart have a negative charge. In order to cause them to contract,they receive an influx of positive ions Na⁺ and Ca⁺⁺. This influx ofpositive ions is called depolarization. The return of negative ions tobring the heart back to a resting state is called repolarization.Depolarization and repolarization of the heart affects different partsof the heart over time giving rise to the P, Q, R, S, T, U, and Jwaveforms.

FIG. 2 is an exemplary plot 200 of the P, Q, R, S, and T waveforms of aconventional ECG waveform of a heartbeat from a conventional ECG device.The P, Q, R, S, and T waveforms represent electrical conduction througha heart muscle. P waveform 210 represents the propagation ofdepolarization from the sinoatrial node, to the right and left atriums,and to the atrioventricular node. The sinoatrial node is also referredto as the sinus node, SA node, or SAN. The atrioventricular node is alsoreferred to as the AV node or AVN. The right atrium is also referred toas the RA, and the left atrium is also referred to as the LA.

FIG. 3 is an exemplary diagram 300 of the depolarization of the muscletissue of a heart that produces P waveform 210 of FIG. 2 as detected bya conventional ECG device. P waveform 210 of FIG. 2 is produced asdepolarization propagates from SAN 310 to AVN 340 in FIG. 3. Asdepolarization propagates from SAN 310 to AVN 340, it also spreads fromRA 320 to LA 340. P waveform 210 of FIG. 2 typically has a duration of80 ms, for example.

PR segment 220 of FIG. 2 represents the propagation of depolarizationfrom the AVN to the Bundle of His, and then to the Bundle Branches. PRsegment 230 may also include depolarization to the Purkinje fibers ofthe inner ventricular walls. The Bundle of His is also referred to asthe His Bundle or His. The Bundle Branches include the right bundlebranches (RBB) and the left bundle branches (LBB). As shown in FIG. 2,in a conventional ECG, PR segment 220 shows up as a flat line orwaveform with no amplitude.

FIG. 4 is an exemplary diagram 400 of the depolarization of the muscletissue of a heart that produces PR segment 220 of FIG. 2 as detected bya conventional ECG device. PR segment 220 of FIG. 2 is produced asdepolarization propagates from AVN 340 to His 450 and then to BundleBranches 460 that include RBB 461 and LBB 462. PR segment 220 of FIG. 2typically has a duration of between 50 and 120 ms, for example.

Waveforms Q 230, R 240, and S 250 of FIG. 2 form the QRS complex. TheQRS complex represents the propagation of depolarization through theright and left ventricles. The right ventricle is also referred to asRV, and the left ventricle is referred to as LV.

FIG. 5 is an exemplary diagram 500 of the depolarization of the muscletissue of a heart that produces Q waveform 230, R waveform 240, and Swaveform 250 of FIG. 2 as detected by a conventional ECG device.Waveforms Q 230, R 240, and S 250 of FIG. 2 produced as depolarizationpropagates from Bundle Branches 460 through RV 571 and LV 572. RV 571and LV 572 have the largest muscle mass in the heart. The QRS complexformed by waveforms Q 230, R 240, and S 250 of FIG. 2 typically has aduration of between 80 and 100 ms, for example.

ST segment 260 of FIG. 2 represents the period during which theventricles remain depolarized and contracted. As shown in FIG. 2, in aconventional ECG, ST segment 260 shows up as a flat line or waveformwith no amplitude. ST segment 260 typically has a duration of between 80and 120 ms, for example.

The point in FIG. 2 at which the QRS complex ends and ST segment 260begins is called J point 255. A J waveform (not shown) can sometimesappear as an elevated J point at J point 255 or as a secondary Rwaveform. A J waveform is usually characteristic of a specific disease.The J waveform is also referred to as the Osborn wave, camel-hump sign,late delta wave, hathook junction, hypothermic wave, prominent J wave, Kwave, H wave or current of injury.

T waveform 270 of FIG. 2 represents the repolarization or recovery ofthe ventricles. T waveform 270 typically has a duration of 160 ms, forexample. The interval between the Q and T waveforms is referred to asthe QT interval.

FIG. 6 is an exemplary diagram 600 of the repolarization of the muscletissue of a heart that produces T waveform 270 of FIG. 2 as detected bya conventional ECG device. As shown in FIG. 6, RV 571 and LV 572 arerepolarized.

Not shown in FIG. 2 is the U waveform. The U waveform sometimes appearsafter the T waveform. The U waveform is thought to representrepolarization of the interventricular septum, the papillary muscles, orthe Purkinje fibers.

As shown in FIGS. 3 through 6, as a heart beats, electrical signals flowthrough all the different muscle tissues of the heart. As shown in FIG.2, for the last 100 years conventional ECG devices have been able todetect some of these signals in the form of the P, Q, R, S, T, U, and Jwaveforms. These waveforms have aided in the diagnosis and treatment ofmany heart problems. Unfortunately, however, the P, Q, R, S, T, U, and Jwaveforms do not provide a complete picture of the operation of all thedifferent muscle tissues of the heart. As a result, improved systems andmethods are needed to detect and analyze more information from theelectrical signals that flow through all the different muscle tissues ofthe heart as it is beating. This additional information can be used todiagnose and treat many more heart problems.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram that illustrates a computer system, inaccordance with various embodiments.

FIG. 2 is an exemplary plot of the P, Q, R, S, and T waveforms of aconventional electrocardiography (ECG) waveform of a heartbeat from aconventional ECG device.

FIG. 3 is an exemplary diagram of the depolarization of the muscletissue of a heart that produces the P waveform of FIG. 2 as detected bya conventional ECG device.

FIG. 4 is an exemplary diagram of the depolarization of the muscletissue of a heart that produces the PR segment of FIG. 2 as detected bya conventional ECG device.

FIG. 5 is an exemplary diagram of the depolarization of the muscletissue of a heart that produces the Q waveform, the R waveform, and theS waveform of FIG. 2 as detected by a conventional ECG device.

FIG. 6 is an exemplary diagram of the repolarization of the muscletissue of a heart that produces the T waveform of FIG. 2 as detected bya conventional ECG device.

FIG. 7 is a block diagram of a conventional ECG device.

FIG. 8 is a block diagram of an ECG device for detecting moreinformation from the electrical signals that flow through all thedifferent muscle tissues of the heart as it is beating, in accordancewith various embodiments.

FIG. 9 is an exemplary plot of a saah ECG waveform of a heartbeat from asaah ECG device showing subwaveforms found within the P, Q, R, S, T, U,and J waveforms and/or within the intervals between the P, Q, R, S, T,U, and J waveforms, in accordance with various embodiments.

FIG. 10 is an exemplary block diagram showing a signal processingalgorithm for detecting five subwaveforms within the PR interval of aconventional ECG waveform, in accordance with various embodiments.

FIG. 11 is an exemplary block diagram of a saah ECG device that displaysconventional ECG waveforms, saah ECG waveforms, and saah ECG data, inaccordance with various embodiments.

FIG. 12 is an exemplary plot of the information displayed by the saahECG device of FIG. 10, in accordance with various embodiments.

FIG. 13 is an exemplary block diagram of a saah ECG device that displaysconventional ECG waveforms, saah ECG waveforms, saah ECG data, and saahECG automatic pattern recognition diagnosis information, in accordancewith various embodiments.

FIG. 14 is a series of photographs of automatic pattern recognitiondiagnosis (APD) information displayed around a rotating button of anexemplary saah ECG device, in accordance with various embodiments.

FIG. 15 is a plot of saah ECG and conventional ECG waveforms taken froma patient suffering from Wolff-Parkinson-White (WPW) syndrome before andafter treatment with radiofrequency ablation (RFA) showing theadditional diagnostic and treatment assessment information provided by asaah ECG device, in accordance with various embodiments.

FIG. 16 is a flowchart showing a method for detecting subwaveformswithin the P, Q, R, S, T, U, and J waveforms of an ECG waveform of aheartbeat or in an interval between the P, Q, R, S, T, U, and Jwaveforms, in accordance with various embodiments.

FIG. 17 is a schematic diagram of a system that includes one or moredistinct software modules that performs a method for detectingsubwaveforms within the P, Q, R, S, T, U, and J waveforms of an ECGwaveform of a heartbeat or in an interval between the P, Q, R, S, T, U,and J waveforms, in accordance with various embodiments.

FIG. 18 is an exemplary block diagram showing a system for performingmulti-domain ECG using 16 different frequency bands or domains, inaccordance with various embodiments.

FIG. 19 is an exemplary plot of a multi-domain ECG waveform thatincludes 10 different time domain signals, in accordance with variousembodiments.

FIG. 20 is an exemplary plot of a multi-domain ECG waveform thatincludes 14 different time domain signals, in accordance with variousembodiments.

FIG. 21 is an exemplary alignment of a multi-domain ECG waveform 2110that includes 16 different time domain signals with a conventional ECGwaveform 2120, in accordance with various embodiments.

FIG. 22 is an exemplary diagram showing portions of the threemulti-domain ECG waveform produced for three different ECG electrodes,I, II, and III, in accordance with various embodiments.

FIG. 23 is an exemplary alignment of multi-domain ECG waveforms measuredfor a patient with a 100% left anterior descending (LAD) artery and 80%right coronary artery (RAC) blockage before and after percutaneouscoronary intervention (PCI, formerly known as angioplasty with stent),in accordance with various embodiments.

FIG. 24 is a flowchart showing a method 2400 for detecting amulti-domain ECG waveform that includes two or more different timedomain signals that each represent a different frequency domain signal,in accordance with various embodiments.

Before one or more embodiments of the invention are described in detail,one skilled in the art will appreciate that the invention is not limitedin its application to the details of construction, the arrangements ofcomponents, and the arrangement of steps set forth in the followingdetailed description. The invention is capable of other embodiments andof being practiced or being carried out in various ways. Also, it is tobe understood that the phraseology and terminology used herein is forthe purpose of description and should not be regarded as limiting.

DETAILED DESCRIPTION Computer-Implemented System

FIG. 1 is a block diagram that illustrates a computer system 100, uponwhich embodiments of the present teachings may be implemented. Computersystem 100 includes a bus 102 or other communication mechanism forcommunicating information, and a processor 104 coupled with bus 102 forprocessing information. Computer system 100 also includes a memory 106,which can be a random access memory (RAM) or other dynamic storagedevice, coupled to bus 102 for storing instructions to be executed byprocessor 104. Memory 106 also may be used for storing temporaryvariables or other intermediate information during execution ofinstructions to be executed by processor 104. Computer system 100further includes a read only memory (ROM) 108 or other static storagedevice coupled to bus 102 for storing static information andinstructions for processor 104. A storage device 110, such as a magneticdisk or optical disk, is provided and coupled to bus 102 for storinginformation and instructions.

Computer system 100 may be coupled via bus 102 to a display 112, such asa cathode ray tube (CRT) or liquid crystal display (LCD), for displayinginformation to a computer user. An input device 114, includingalphanumeric and other keys, is coupled to bus 102 for communicatinginformation and command selections to processor 104. Another type ofuser input device is cursor control 116, such as a mouse, a trackball orcursor direction keys for communicating direction information andcommand selections to processor 104 and for controlling cursor movementon display 112. This input device typically has two degrees of freedomin two axes, a first axis (i.e., x) and a second axis (i.e., y), thatallows the device to specify positions in a plane.

A computer system 100 can perform the present teachings. Consistent withcertain implementations of the present teachings, results are providedby computer system 100 in response to processor 104 executing one ormore sequences of one or more instructions contained in memory 106. Suchinstructions may be read into memory 106 from another computer-readablemedium, such as storage device 110. Execution of the sequences ofinstructions contained in memory 106 causes processor 104 to perform theprocess described herein. Alternatively hard-wired circuitry may be usedin place of or in combination with software instructions to implementthe present teachings. Thus implementations of the present teachings arenot limited to any specific combination of hardware circuitry andsoftware.

In various embodiments, computer system 100 can be connected to one ormore other computer systems, like computer system 100, across a networkto form a networked system. The network can include a private network ora public network such as the Internet. In the networked system, one ormore computer systems can store and serve the data to other computersystems. The one or more computer systems that store and serve the datacan be referred to as servers or the cloud, in a cloud computingscenario. The other computer systems that send and receive data to andfrom the servers or the cloud can be referred to as client or clouddevices, for example.

The term “computer-readable medium” as used herein refers to any mediathat participates in providing instructions to processor 104 forexecution. Such a medium may take many forms, including but not limitedto, non-volatile media, volatile media, and transmission media.Non-volatile media includes, for example, optical or magnetic disks,such as storage device 110. Volatile media includes dynamic memory, suchas memory 106. Transmission media includes coaxial cables, copper wire,and fiber optics, including the wires that comprise bus 102.

Common forms of computer-readable media or computer program productsinclude, for example, a floppy disk, a flexible disk, hard disk,magnetic tape, or any other magnetic medium, a CD-ROM, digital videodisc (DVD), a Blu-ray Disc, any other optical medium, a thumb drive, amemory card, a RAM, PROM, and EPROM, a FLASH-EPROM, any other memorychip or cartridge, or any other tangible medium from which a computercan read.

Various forms of computer readable media may be involved in carrying oneor more sequences of one or more instructions to processor 104 forexecution. For example, the instructions may initially be carried on themagnetic disk of a remote computer. The remote computer can load theinstructions into its dynamic memory and send the instructions over atelephone line using a modem. A modem local to computer system 100 canreceive the data on the telephone line and use an infra-red transmitterto convert the data to an infra-red signal. An infra-red detectorcoupled to bus 102 can receive the data carried in the infra-red signaland place the data on bus 102. Bus 102 carries the data to memory 106,from which processor 104 retrieves and executes the instructions. Theinstructions received by memory 106 may optionally be stored on storagedevice 110 either before or after execution by processor 104.

In accordance with various embodiments, instructions configured to beexecuted by a processor to perform a method are stored on acomputer-readable medium. The computer-readable medium can be a devicethat stores digital information. For example, a computer-readable mediumincludes a compact disc read-only memory (CD-ROM) as is known in the artfor storing software. The computer-readable medium is accessed by aprocessor suitable for executing instructions configured to be executed.

The following descriptions of various implementations of the presentteachings have been presented for purposes of illustration anddescription. It is not exhaustive and does not limit the presentteachings to the precise form disclosed. Modifications and variationsare possible in light of the above teachings or may be acquired frompracticing of the present teachings. Additionally, the describedimplementation includes software but the present teachings may beimplemented as a combination of hardware and software or in hardwarealone. The present teachings may be implemented with bothobject-oriented and non-object-oriented programming systems.

Subwaveform Detection of the P, Q, R, S, T, U, and J Waveforms

As described above, electrical signals flow through all the differentmuscle tissues of the heart. For the last 100 years conventional ECGdevices have been able to detect some of these signals in the form ofthe P, Q, R, S, T, U, and J waveforms. These waveforms have aided in thediagnosis and treatment of many heart problems.

Unfortunately, however, the P, Q, R, S, T, U, and J waveforms do notprovide a complete picture of the operation of all the different muscletissues of the heart. As a result, improved systems and methods areneeded to detect and analyze more information from the electricalsignals that flow through all the different muscle tissues of the heartas it is beating. This additional information can be used to diagnoseand treat many more heart problems.

In various embodiments, additional information is obtained from theelectrical signals produced by a heart through signal processing. Morespecifically, signal processing is added to an ECG device in order todetect more information from the electrical signals that flow throughall the different muscle tissues of the heart as it is beating.

FIG. 7 is a block diagram 700 of a conventional ECG device. Theconventional ECG device includes two or more leads or electrodes 710.Electrodes 710 are typically attached to the skin of a patient.Electrical signals produced by a beating heart are detected betweenpairs of electrodes 710. Because the heart is three-dimensional,electrodes are attached at different locations on a body to detectsignals at different corresponding locations or angles from the heart.In other words, the electrodes are placed on a body to partiallysurround the heart. One typical type of ECG includes 12 electrodes, forexample.

A voltage signal is detected between two electrodes 710 by detector 720.Detector 720 also typically amplifies the voltage signal. Detector 720can also convert the voltage signal to a digital voltage signal using ananalog to digital converter (A/D).

Detector 720 provides the detected and amplified voltage signal fromeach pair of electrodes 710 to display 730. Display 730 can be anelectronic display device including, but not limited to, a cathode raytube (CRT) device, light emitting diode (LED) device, or Liquid crystaldisplay (LCD) device. Display 730 can also be a printer device.Additionally, display 730 can include a memory device to record detectedsignals. The memory device can be, but is not limited to, a volatileelectronic memory, such as random access memory (RAM), a non-volatileelectronic memory, such as electrically erasable programmable read-onlymemory (EEPROM or Flash memory), or a magnetic hard drive.

Display 730 displays a continuous loop of the detected P, Q, R, S, T, U,and J waveforms as shown in FIG. 2 for each pair of electrodes 710.Modern ECG devices can also include a processor (not shown), such as theprocessor shown in FIG. 1, to analyze the P, Q, R, S, T, U, and Jwaveforms. For example, the processor can calculate the time periods ofthe P, Q, R, S, T, U, and J waveforms and the times between the P, Q, R,S, T, U, and J waveforms. The processor can also compare this timinginformation to stored normal information. Based on the comparison, theprocessor can determine differences from the normal data. Allinformation calculated by the processor can also be displayed on display730.

FIG. 8 is a block diagram 800 of an ECG device for detecting moreinformation from the electrical signals that flow through all thedifferent muscle tissues of the heart as it is beating, in accordancewith various embodiments. Electrodes 810 are attached to the skin of apatient, for example. Electrical signals produced by a beating heart aredetected between pairs of electrodes 810.

A voltage signal is detected between two electrodes 810 by detector 820.Detector 820 also amplifies the voltage signal. Detector 820 alsoconverts the voltage signal to a digital voltage signal using an analogto digital converter (A/D).

Detector 820 provides the detected and amplified voltage signal fromeach pair of electrodes 810 to signal processor 830. Detector 820 canalso provide the detected and amplified voltage signal from each pair ofelectrodes 810 directly to display device 840 to display theconventional P, Q, R, S, T, U, and J waveforms.

Signal processor 830 detects or calculates one or more subwaveformswithin and/or in the interval between the P, Q, R, S, T, U, and Jwaveforms of each detected and amplified voltage signal. A waveform is ashape or form of a signal. A subwaveform is shape or form of a signalthat is within or part of another signal.

Signal processor 830 can be a separate electronic device that caninclude, but is not limited to, an application specific integratedcircuit (ASIC), a field programmable gate array (FPGA), or a generalpurpose processor. Signal processor 830 can be software implemented onanother processor of the ECG device, such as a processor of displaydevice 840. Signal processor 830 can also be a remote server thatreceives the detected and amplified voltage signal from detector 820,detects or calculates one or more subwaveforms within and/or in theinterval between the P, Q, R, S, T, U, and J waveforms, and sends thedetected and amplified voltage signal and the one or more subwaveformsto display device 840.

Signal processor 830 sends one or more subwaveforms of each detected andamplified voltage signal to display device 840. Signal processor 830 canalso calculate and send to the display device 840 the time periods ofthe one or more subwaveforms, the times between the one or moresubwaveforms, and the times of the one or more subwaveforms in relationto the P, Q, R, S, T, U, and J waveforms and or the intervals betweenthe P, Q, R, S, T, U, and J waveforms. Signal processor 830 can alsocompare this timing information to stored normal timing information.Based on the comparison, signal processor can determine differences fromthe normal data and send this difference information and any of thetiming information to display device 840.

Display device 840 displays a continuous loop of the one or moresubwaveforms for each pair of electrodes 810. Display device 840 canalso display part or all of the conventional P, Q, R, S, T, U, and Jwaveforms for comparison with the one or more subwaveforms. Like display730 of FIG. 7, display device 840 of FIG. 8 can be an electronic displaydevice, a printer, or any combination of the two.

In various embodiments, an ECG device using signal processing to detectone or more subwaveforms within the P, Q, R, S, T, U, and J waveformsand/or within the intervals between the P, Q, R, S, T, U, and Jwaveforms is herein referred to as a saah ECG device. The voltagedifference signals produced by a saah ECG device are referred to as saahECG waveforms. The term “saah” is an acronym for some of theanatomically distinct portions of muscle tissue that producesubwaveforms. Specifically, saah stands for sinoatrial node (SAN), atria(right atrium (RA) and left atrium (LA)), atrioventricular node (AVN),and bundle of His (HIS). However, a saah ECG waveform is not limited toincluding subwaveforms representing the SAN, the atria, the AVN, and theHIS. A saah ECG waveform can include any subwaveform the P, Q, R, S, T,U, and J waveforms and/or within the intervals between the P, Q, R, S,T, U, and J waveforms.

FIG. 9 is an exemplary plot 900 of a saah ECG waveform of a heartbeatfrom a saah ECG device showing subwaveforms found within the P, Q, R, S,T, U, and J waveforms and/or within the intervals between the P, Q, R,S, T, U, and J waveforms, in accordance with various embodiments. Forexample, five subwaveforms 910-950 of FIG. 9 are detected within the Pwaveform and the PR segment. The time period that includes the Pwaveform and the PR segment is also called the PR interval. Subwaveform910 represents the depolarization of the SAN. Subwaveform 920 representsthe depolarization of RA and LA. Subwaveform 930 represents thedepolarization of the AVN. Subwaveform 940 represents the depolarizationHIS. Finally, subwaveform 950 represents the depolarization of thebundle branches (BB).

In various embodiments, the subwaveforms of a saah ECG waveform aredetected using signal processing. Electrodes 810 of the saah ECG of FIG.8, for example, receive electrical impulses from anatomically distinctportions of muscle tissue or cells. The electrical impulses ofanatomically distinct portions of muscle tissue of the heart havedistinct frequencies. Through animal and human experimentation, thedistinct frequency, frequency range, or frequency band of theanatomically distinct portions of muscle tissue of the heart are found.These distinct frequency bands of anatomically distinct portions ofmuscle tissue of the heart provide predetermined data or information forsignal processing. In other words, the band pass frequency filtering ofthe signal processing is determined from the experimental datacollected. A saah ECG device then employs one or more frequency bandpass filters to detect the one or more subwaveforms.

FIG. 10 is an exemplary block diagram 1000 showing a signal processingalgorithm for detecting five subwaveforms within the PR interval of aconventional ECG waveform, in accordance with various embodiments.Sampling block 1010 samples the electrical impulses in the PR intervaltime period of each heart. This is shown graphically in FIG. 1000 byseparating PR interval 1020 from ECG waveform 200. The electricalimpulses in the PR interval time period are sampled using electrodes 810and detector 820 of FIG. 8, for example. Detector 820 of FIG. 8 can alsoamplify and convert the analog signal into a digital signal for digitalprocessing.

The signal processing can be performed directly on the time domainsignal received from a detector or the time domain signal received froma detector can be converted to the frequency domain for algorithmicprocessing. In FIG. 10, block 1030 converts the PR interval time domainsignal to a PR interval frequency domain signal. The time domain signalis converted into a frequency domain signal using a Fourier transform,for example.

As described above, through animal and/or human experimentation, thefrequency bands associated with depolarization of the SAN, atria, AVN,HIS, and BB of the heart are determined. Based on these frequency bands,band pass filters are created. Blocks 1041-1045 represent the band passfilters created to filter the PR interval frequency domain signal forfrequency bands of the SAN, atria, AVN, HIS, and BB of the heart,respectively.

In block 1050, the frequency domain subwaveforms detected from the bandpass filtering the frequency bands of the SAN, atria, AVN, HIS, and BBof the heart are summed. In block 1060, the filtered and summedfrequency domain signal of the PR interval is converted back to a timedomain signal. The frequency domain signal is converted into a timedomain signal using a Fourier transform, for example.

The PR interval filtered and summed time domain signal 1070 includesfive time domain subwaveforms 910-950. Subwaveforms 910-950 representdepolarization of the SAN, atria, AVN, HIS, and BB of the heart,respectively. Time domain signal 1070 can be used to replace PR interval1020 in ECG waveform 200, for example. As a result, a saah ECG waveformis produced.

FIG. 10 shows a signal processing algorithm for detecting fivesubwaveforms. However, similar steps can be applied to detect fewer thanfive waveforms or more than five waveforms. Also, the steps of FIG. 10describe detecting subwaveforms within the PR interval. However, similarsteps can be applied to detect subwaveforms within the P, Q, R, S, T, U,and J waveforms and/or within one or more of the intervals between theP, Q, R, S, T, U, and J waveforms. In addition, the steps of FIG. 10describe converting time signals to the frequency domain and then backto the time domain. One of ordinary skill in the art can appreciate thatband pass filters can be applied directly to the time domain signal toprovide the same result.

FIG. 11 is an exemplary block diagram 1100 of a saah ECG device thatdisplays conventional ECG waveforms, saah ECG waveforms, and saah ECGdata, in accordance with various embodiments. In block 1110, patientheart signals are obtained. These heart signals can be obtained throughnoninvasive electrodes placed on the skin, such as electrodes 810 showin FIG. 8. In various embodiments, heart signals may also be obtainedusing invasive electrodes placed directly on the heart. In block 1120,the heart signals are detected using a detector and amplified.

In block 1130, the detected and amplified heart signals are processedusing a signal processor. The signal processor detects the conventionalP, Q, R, S, T, U, and J waveforms and sends them to the display of block1160. The signal processor also detects or calculates subwaveformswithin the conventional P, Q, R, S, T, U, and J waveforms and/or withinintervals between the conventional P, Q, R, S, T, U, and J waveforms.The signal processor sends the subwaveforms to block 1140 for furtherprocessing. The processor of block 1140 produces the saah ECG waveformthat includes the subwaveforms and sends the saah ECG waveform to thedisplay of block 1160. The processor of block 1140 calculates additionalinformation or new data from the saah ECG waveform. This new data caninclude, but is not limited to, timing information about thesubwaveforms, timing information about the intervals between thesubwaveforms, and timing information about the subwaveforms and theirrelation to the conventional P, Q, R, S, T, U, and J waveforms. In block1150, this new data is sent to the display of block 1160.

The display of block 1160 displays a continuous loop of the conventionalECG waveform, the saah ECG waveform, and the new data from thesubwaveforms. The display of block 1160 can display this information onan electronic display or print it on paper. The display of block 1160can also record this information. The display of block 1160 can recordthis information on any type of memory device.

FIG. 12 is an exemplary plot 1200 of the information displayed by thesaah ECG device of FIG. 11, in accordance with various embodiments. Plot1200 includes conventional ECG waveform 1210 and saah ECG waveform 1220.Saah ECG waveform 1220, for example, includes, among others, fivesubwaveforms A-E representing the depolarization of the SAN, the RA andLA, the AVN, the HIS, and the BB, respectively.

Plot 1200 also shows new data or timing information about thesubwaveforms and their relation to the conventional P, Q, R, S, T, U,and J waveforms. For example, the time interval between line 1231 andline 1232 relates subwaveform A of saah ECG waveform 1220 to P waveform1240 of conventional ECG waveform 1210. The time interval between line1232 and line 1233 relates subwaveforms B and C of saah ECG waveform1220 to P waveform 1240 conventional ECG waveform 1210. The timeinterval between line 1233 and line 1234 relates subwaveforms D and E ofsaah ECG waveform 1220 to PR segment 1250 conventional ECG waveform1210.

FIG. 13 is an exemplary block diagram 1300 of a saah ECG device thatdisplays conventional ECG waveforms, saah ECG waveforms, saah ECG data,and saah ECG automatic pattern recognition diagnosis information, inaccordance with various embodiments. In block 1310, patient heartsignals are obtained. These heart signals can be obtained throughnoninvasive electrodes placed on the skin, such as electrodes 810 showin FIG. 8. In various embodiments, heart signals may also be obtainedusing invasive electrodes placed directly on the heart. In block 1320,the heart signals are sampled or detected using a detector. The heartsignals may also be amplified.

In block 1330, the sampled heart signals are processed using a signalprocessor. The signal processor produces four different types ofinformation from the sampled heart signals. As shown in block 1340, thesignal processor produces conventional ECG waveforms including theconventional P, Q, R, S, T, U, and J waveforms and sends them to display1380. As shown in block 1350, the signal processor produces saah ECGwaveforms. These saah ECG waveforms include subwaveforms of theconventional P, Q, R, S, T, U, and J waveforms and the intervals betweenthem. Note that the arrow between blocks 1330 and 1350 show informationfollowing in both directions. This shows that information from the saahECG waveforms is further analyzed by the signal processor.

As shown in block 1360, the signal processor further analyzes the saahECG waveforms to produce saah ECG data. This saah ECG data is sent todisplay 1380. Additionally, as shown in block 1370, the signal processorfurther analyzes the saah to obtain endocardium and epicardium data.This data is compared to recorded normal and abnormal data. The signalprocessor then produces automatic pattern recognition diagnosis (APD)information, and this information is sent to display 1380. APDinformation is, for example, patterns and/or colors that allows a userto easily and quickly determine that normal or abnormal endocardiumand/or epicardium data was found.

FIG. 14 is a series 1400 of photographs of automatic pattern recognitiondiagnosis (APD) information displayed around a rotating button of anexemplary saah ECG device, in accordance with various embodiments.Photograph 1410 shows information 1415 displayed around rotating button1401. Information 1415 includes a pattern and colors that indicate anormal state of the saah ECG waveforms. Photograph 1420 showsinformation 1425 displayed around rotating button 1401. Information 1425includes a pattern and colors that indicate a suspicious state of thesaah ECG waveforms. Photograph 1430 shows information 1435 displayedaround rotating button 1401. Information 1435 includes a pattern andcolors that indicate an abnormal state of the saah ECG waveforms.Photograph 1440 shows information 1445 displayed around rotating button1401. Information 1445 includes a pattern and colors that indicate aninvalid result in the saah ECG waveforms.

In various embodiments, the additional information provided by a saahECG device can be used to diagnose heart problems that cannot bediagnosed using conventional ECG devices or cannot easily be diagnosedusing conventional ECG devices. The additional information provided by asaah ECG device can also be used in the treatment of heart problems orthe assessment of these treatments.

FIG. 15 is a plot 1500 of saah ECG and conventional ECG waveforms takenfrom a patient suffering from Wolff-Parkinson-White (WPW) syndromebefore and after treatment with radiofrequency ablation (RFA) showingthe additional diagnostic and treatment assessment information providedby a saah ECG device, in accordance with various embodiments. WPWsyndrome is caused by the presence of abnormal electrical pathways inthe heart muscle tissue. There are, at least, three different types ofabnormal pathways. These abnormal pathways cause cardiac tachycardia.Cardiac tachycardia is an abnormally rapid heart rate.

Plot 1500 shows before saah ECG waveform 1510, before conventional ECGwaveform 1520, after saah ECG waveform 1530, and after conventional ECGwaveform 1540. Waveforms 1510, 1520, 1530, and 1540 are produced forexample using a saah ECG device. A saah ECG device also producesconventional ECG waveforms for comparison with the saah ECH waveforms.Waveforms 1510, 1520, 1530, and 1540 are produced using a V4 electrode,for example. A V4 electrode is placed in the fifth intercostal space(between ribs 5 and 6) in the mid-clavicular line, for example.

As described above, saah ECG waveforms show subwaveforms of theconventional P, Q, R, S, T, U, and J waveforms and the intervals betweenthem. These subwaveforms provide more information on the function ofspecific and anatomically distinct portions of the muscle tissue of theheart.

For example, arrows 1503 and 1506 point to areas of two beats of beforesaah ECG waveform 1510 where the subwaveform showing the depolarizationof the bundle branches (BB) is missing. Arrows 1501, 1502, 1504, and1505 point to areas of four beats where the subwaveform showing thedepolarization of the BB appears as half of the normal subwaveform. As aresult, in two of the six beats of before ECG waveform 1510 thesubwaveform representing the BB is missing, and in four of the six beatsof before saah ECG waveform 1510 the subwaveform representing the BB isabnormal. A normal subwaveform representing the BB has a shape, forexample, like subwaveform 950 of FIG. 9.

This information from before saah ECG waveform 1510 of FIG. 15 regardingthe BB can be used to diagnose the specific abnormal pathway present inthis case of WPW syndrome. Further this information can be used todetermine the treatment. In contrast, none of this information can beobtained from before conventional ECG waveform 1520.

In addition to providing a saah ECG waveform, a saah ECG device canprovide additional data regarding the subwaveforms found. For example,plot 1500 includes subwaveform timing information for the PR interval ofeach heartbeat. This timing information is provided as timing diagrams1551-1556 for the six heartbeats. Each timing diagram provides a numeralvalue for the period of the PR interval and a horizontal stacked bargraph depicting how four time intervals containing one or moresubwaveforms are distributed with PR interval time period. Thehorizontal stacked bar graphs can include different colors, patterns, orshades, for example.

The first interval of each horizontal stacked bar graph is the intervalthat includes the subwaveform representing the depolarization of thesinoatrial node (SAN). The second interval is the interval that includesthe subwaveforms representing the depolarization of the atria (rightatrium (RA) and left atrium (LA)) and the atrioventricular node (AVN).The third interval is the interval that includes the subwaveformrepresenting the depolarization of the bundle of His (HIS) of thebeating heart. The fourth interval is the interval that includes thesubwaveform representing the depolarization of the bundle branches (BB).

A comparison of the horizontal stacked bar graphs of timing diagrams1551-1556 shows that the periods of the four intervals vary widely overthe six heartbeats. This is also an indication of the underlyingdisease. This timing information is not available in before conventionalECG waveform 1520.

RFA was performed on the patient presenting before saah ECG waveform1510 and before conventional ECG waveform 1520. A muscular conductionbridge connecting the right atrium and the right ventricle (bundle ofKent) and a connections between the A-V bundle and the interventricularseptum (Mahaim's connections) were ablated, for example.

After treatment with RFA, the patient's return to a normal heartbeat canbe confirmed with after saah ECG waveform 1530. For example, arrows1531-1536 of the six heartbeats shown in after saah ECG waveform 1530point to areas that show that the subwaveform of the BB has returned inall six heartbeats after treatment. In contrast, after conventional ECGwaveform 1540 cannot provide this information.

In addition, a comparison of the horizontal stacked bar graphs of timingdiagrams 1571-1576 for after saah ECG waveform 1530 shows that theperiods of the four intervals of the PR interval do not vary widely overthe six heartbeats. This is also an indication of the effectiveness ofthe RFA treatment. This timing information is not available in afterconventional ECG waveform 1540.

System for Detecting ECG Subwaveforms

In various embodiments, an electrocardiography (ECG) system fordetecting one or more subwaveforms within the P, Q, R, S, T, U, and Jwaveforms or in an interval between the P, Q, R, S, T, U, and Jwaveforms is provided. Returning to FIG. 8, the ECG system includes twoor more electrodes 810, a detector 820, a signal processor 830, and adisplay device 840.

Two or more electrodes 810 are placed proximate to a beating heart thatreceive electrical impulses from the beating heart. Two or moreelectrodes 810 are shown in FIG. 8 as noninvasive electrodes that areattached to the skin of a patient. In various embodiments, two or moreelectrodes 810 can be invasive electrodes placed directly on or withinheart tissue.

Detector 820 is electrically connected to two or more electrodes 810.Detector 820 detects the electrical impulses from at least one pair ofelectrodes of the two or more electrodes 810. Detector 820 converts theelectrical impulses to an ECG waveform for each heartbeat of the beatingheart. Detector 820, for example, samples the electrical impulses. Invarious embodiments, detector 820 further amplifies the ECG waveform. Invarious embodiments, detector 820 further performs analog to digital(A/D) conversion on the ECG waveform. In various embodiments, detector820 provides an ECG waveform with a higher signal-to-noise (S/N) ratiothan conventional ECG devices.

Signal processor 830 is electrically connected to detector 820. Signalprocessor receives the ECG waveform from detector 820. Signal processor830 detects or calculates one or more subwaveforms within P, Q, R, S, T,U, and J waveforms of the ECG waveform or in an interval between the P,Q, R, S, T, U, and J waveforms that represent the depolarization orrepolarization of anatomically distinct portions of muscle tissue of thebeating heart. Signal processor 830 produces a processed ECG waveformthat includes the one or more subwaveforms for each heartbeat.

Signal processor 830 can be a separate device, can be software runningon device of detector 820 or display device 840, or can be softwarerunning on a remote server and communicating with detector 820 anddisplay device 840 through one or more communication devices. Signalprocessor 830 can be a separate device that includes, but is not limitedto, an application specific integrated circuit (ASIC) or a fieldprogrammable gate array (FPGA) or a general purpose processor. A generalpurpose processor can include, but is not limited to, a microprocessor,a micro controller, or a computer such as the system shown in FIG. 1.Signal processor 830 can be software implemented on another processor ofthe ECG device, such as a processor of display device 840. Signalprocessor 830 can also be a remote server that receives the detected andamplified difference voltage signal from detector 820, detects orcalculates one or more subwaveforms within and/or in the intervalbetween the P, Q, R, S, T, U, and J waveforms, and sends the detectedand amplified different voltage signal and the one or more subwaveformsto display device 840.

Display device 840 receives the processed ECG waveform for eachheartbeat and displays the processed ECG waveform for each heartbeat.The processed ECG waveform is called a saah ECG waveform, for example.As described above, display device 840 can be an electronic displaydevice including, but not limited to, a cathode ray tube (CRT) device,light emitting diode (LED) device, or Liquid crystal display (LCD)device. Display device 840 can also be a printer device or anycombination of an electronic display device and a printer. Additionally,display device 840 can include a memory device to record saah ECGwaveforms, saah ECG data and conventional ECG waveforms and data. Thememory device can be, but is not limited to, a volatile electronicmemory, such as random access memory (RAM), a non-volatile electronicmemory, such as electrically erasable programmable read-only memory(EEPROM or Flash memory), or a magnetic hard drive.

In various embodiments, the detected one or more subwaveforms include atleast one subwaveform representing depolarization of the sinoatrial node(SAN), the atria (right atrium (RA) and left atrium (LA)), theatrioventricular node (AVN), the bundle of His (HIS), or the bundlebranches (BB) of the beating heart.

In various embodiments, the display device 840 further displays the ECGwaveform for comparison with the processed ECG waveform.

In various embodiments, signal processor 830 further calculates timinginformation about the one or more subwaveforms, timing information aboutthe intervals between the one or more subwaveforms, and timinginformation about the one or more subwaveforms and their relation to theP, Q, R, S, T, U, and J waveforms of the ECG waveform for eachheartbeat. Display device 840 further receives this timing informationfrom signal processor 830. Display device 840 displays the timinginformation about the one or more subwaveforms, the timing informationabout the intervals between the one or more subwaveforms, and the timinginformation about the one or more subwaveforms and their relation to theP, Q, R, S, T, U, and J waveforms of the ECG waveform for eachheartbeat.

In various embodiments the ECG system further includes a memory device(not shown). The memory device receives the ECG waveform and theprocessed ECG waveform from the signal processor.

In various embodiments, the memory device further includes normalprocessed ECG waveform data. Normal processed ECG waveform data isstored on the memory device using signal processor 830 or a generalpurpose processor (not shown). Signal processor 830 further compares theprocessed ECG waveform to the normal processed ECG waveform data andcalculates a status condition based on the comparison. The statusconditions are, for example, normal, suspicious, or abnormal.

In various embodiments, the ECG system includes a second display device(not shown) surrounding a rotating button (not shown). Signal processor830 further sends a colored pattern to the second display device basedon the status condition. The second display device provides automaticpattern recognition diagnosis (APD).

Method for Detecting ECG Subwaveforms

FIG. 16 is a flowchart showing a method 1600 for detecting subwaveformswithin the P, Q, R, S, T, U, and J waveforms of an ECG waveform of aheartbeat or in an interval between the P, Q, R, S, T, U, and Jwaveforms, in accordance with various embodiments.

In step 1610 of method 1600, electrical impulses are detected between atleast one pair of electrodes of two or more electrodes placed proximateto a beating heart using a detector. The electrical impulses areconverted to an ECG waveform for each heartbeat of the beating heartusing the detector.

In step 1620, the ECG waveform for each heartbeat is received from thedetector using a signal processor. One or more subwaveforms within P, Q,R, S, T, U, and J waveforms of the ECG waveform for each heartbeat or inan interval between the P, Q, R, S, T, U, and J waveforms that representthe depolarization or repolarization of an anatomically distinct portionof muscle tissue of the beating heart are detected using the signalprocessor. A processed ECG waveform that includes the one or moresubwaveforms for each heartbeat is produced using the signal processor.

In step 1630, the processed ECG waveform is received from the signalprocessor and the processed ECG waveform is displayed using a displaydevice.

Computer Program Product for Detecting ECG Subwaveforms

In various embodiments, computer program products include a tangiblecomputer-readable storage medium whose contents include a program withinstructions being executed on a processor so as to perform a method fordetecting subwaveforms within the P, Q, R, S, T, U, and J waveforms ofan ECG waveform of a heartbeat or in an interval between the P, Q, R, S,T, U, and J waveforms. This method is performed by a system thatincludes one or more distinct software modules.

FIG. 17 is a schematic diagram of a system 1700 that includes one ormore distinct software modules that performs a method for detectingsubwaveforms within the P, Q, R, S, T, U, and J waveforms of an ECGwaveform of a heartbeat or in an interval between the P, Q, R, S, T, U,and J waveforms, in accordance with various embodiments. System 1700includes detection module 1710, processing module 1720, and displaymodule 1730.

Detection module 1710 detects electrical impulses between at least onepair of electrodes of two or more electrodes placed proximate to abeating heart. Detection module 1710 converts the electrical impulses toan ECG waveform for each heartbeat of the beating heart.

Processing module 1720 receives the ECG waveform for each heartbeat.Processing module 1720 detects one or more subwaveforms within P, Q, R,S, T, U, and J waveforms of the ECG waveform for each heartbeat or in aninterval between the P, Q, R, S, T, U, and J waveforms that representthe depolarization or repolarization of an anatomically distinct portionof muscle tissue of the beating heart. Processing module 1720 produces aprocessed ECG waveform that includes the one or more subwaveforms foreach heartbeat.

Display module 1730 receives the processed ECG waveform. Display module1730 displays the processed ECG waveform.

Multi-Domain ECG

The heart muscle, like other muscles, is activated by biologicallygenerated electrical signals. Electrocardiography (ECG or EKG) has longbeen used to measure and record these electrical signals. Essentially,in ECG the electrical activity of the heart is measured from a number ofdifferent points on the body and plotted over time. As a result, ECGtraces out each cardiac cycle or heartbeat as a voltage versus timewaveform.

A human heart has two functional systems. The first system, referred toas a self-conduction system, is part of the atrium (including left andright atria). In a traditional ECG, the self-conduction system isrepresented by the P wave or PR interval. The excitation, rhythm andconduction of every beat is completed by the collaboration of all partsof the heart, which is an axis system, including: sinoatrial node(SAN)-atrial-atrioventricular node (AVN)-Bundle of His-Bundle Branches(left and right). The Bundle of His is a collection of heart musclecells specialized for electrical conduction that transmits theelectrical impulses from the AVN to the point of the apex of thefascicular branches. Complex arrhythmias disease typically occurs inthese different areas. However, ECG is only half of a sine wave.

The second system, referred to as a cardiac work system, is a pumpsystem (one for each complete contraction and relaxation of the heart),which is done by the heart muscles. The main part of the second systemis the left ventricle. In the traditional ECG, it is represented by theT wave or QT interval. There are about 10 million ventricular myocardialcells, without nerves or tracts.

Features or waves of each heartbeat waveform have been known for morethan a century to correspond to electrical signals activating variousparts of the heart. For example, the P wave is known to result from anelectrical signal directed from the SAN to the AV node activating theatrium of the heart, to the Bundle of His to the left and right BundleBranches, and the T wave is known to result from a recovery electricalsignal (ventricular depolarization and repolarization) sent to theventricles of the heart after they have contracted. As a result,physicians are able to diagnose specific heart problems by analyzing theshapes and time of these waves.

It is thought that an ECG heartbeat waveform includes much moreinformation about the anatomy of the heart that is not being used(scanning and displaying). In particular, it is thought that at leastsome of the waves in an ECG heartbeat waveform include subwaveforms thatprovide more detailed information about parts of the heart, as describedabove. Consequently, there is a need for systems and methods forprocessing biological electrical signals, such as signals read by ECG,in order to provide additional information about anatomical structures.

Also, electrocardiogram information itself contains a lot of informationthat has not been discovered so far, leaving numerous puzzles in aclinical application.

In various embodiments, new waveforms are created from a conventionalECG waveform. New indexes and new parameters are obtained from the newwaveforms, so that it is possible to have breakthrough inelectrocardiogram diagnostics.

In various embodiments, heart signals are divided into differentfrequency bands, and then convolved or combined in one diagram. Forexample, 16 different frequency bands can be used. This procedure isbased on the study of ergonomics and analysis procedures for frequentlyused information in cybernetics and nonlinear theory. The proceduremakes use of the theory and analysis index of an “electrocardiogrammulti-phase signal,” and by using a new method of frequency division anddimension division, according to the display method of P, Q, R, S, T, U,and J waveforms P-QRS-T in a conventional ECG waveform. Heart diseasesare also related to and/or complicated by different other diseases.Therefore, different numbers of frequency ranges are required to bedisplayed as a diagnostic requirement, because the frequency shifts ofvarious diseases are different. In the multi-domain frequency divisionmethod, 8, 9, 10, 11, 12, 13, 14, 15, or 16 roots of multi-domain linearwaveforms are displayed, and total of 12 leads are individuallydisplayed. If each lead is divided into 16 waveforms, there are totally192 ECG waveforms, providing much more information. In variousembodiments, multi-domain ECG (mdECG) can be used as a very valuable andnew diagnostic technique for combined heart diseases. This technique canbe applied in electrocardiograph, monitor, echocardiography, andinvasive electrophysiological instrument.

Since the invention of ECG, the linear waveform shaped like a rope hasbeen used. Its frequency response range is 0-150 Hz and all subwaveformsare convolved or combined together. However, heart signals are formed bycombining different ultra-low frequency, low frequency, intermediatefrequency, high frequency, and ultra-high frequency signals. Because inECG all frequencies are convolved together, many fine, weak, and veryvaluable signals are usually submerged or overlapped by the highfrequency; especially at ventricle (ECG at T-wave, ECG ‘T’ waveduration) and atrium (ECG at P-wave, ECG ‘P’ wave duration), andnumerous signals accumulate within a very small time axis range, causingproblems and confusion in accuracy of ECG diagnosis rate. As a result,the detection rate of ECG for acute myocardial infarction (AMI), acutecoronary syndrome (ACS), coronary artery disease (CAD), myocardialinfarction (MI), heart failure (HF) etc., with the highest incidence ofcardiovascular disease is only 17%-25%. Based on a large number ofliteratures and research reports, for the CAD/MI/ACS patient, ECG beginsto change only after ischemia reaches 70%, and only about half of theelectrocardiograms show abnormality. There are 7 billion people in theworld, and the percentage of people who die of cardiovascular diseasesor complicated cardiovascular diseases is about 42.86% (3/7).Electrocardiogram is the most fundamental clinical assessmentinstrument, and it is simple, fast and economical. Therefore, it isimportant to improve the clinical ECG diagnosis rate, which is possibleonly by improving the waveform display rate of ECG.

In various embodiments, systems and methods improve the waveform displayrate of ECG and clinical diagnosis rate using a 16 linear multi-domainelectrocardiogram. Because the heart signals are separated according todifferent frequency bands with frequency bands being recombined, manyhigh frequency signal, ultra-high frequency signal, low frequencysignal, and ultra-low frequency signal are displayed with the heart rawsignals at different frequency band according to the heart transductionpathway and electrophysiological rule, without the electrocardiogrambeing altered, i.e., at X-transverse axis and Y-vertical axis ofP-QRS-T. Because the frequency bands of ECG are combined signals, mdECGseparates the signals, i.e., separates them into independent waveformsconsisting of different frequency bands. In this way, those frequencybands with the one linear waveform invisible and obscure in traditionalECG can be displayed clearly with different frequency bands one by one,assisting the doctor in reading, analyzing, judging and basic clinicalassessment.

FIG. 18 is an exemplary block diagram 1800 showing a system forperforming multi-domain ECG using 16 different frequency bands ordomains, in accordance with various embodiments. Sampling block 1810samples the electrical impulses at one electrode for one heartbeat, forexample. This is shown graphically in FIG. 1800 by converting ECGwaveform 200 to sampled ECG waveform 1820 using block 1810. Theelectrical impulses for the entire ECG waveform 200 are sampled usingelectrodes 810 and detector 820 of FIG. 8, for example. Detector 820 ofFIG. 8 can also amplify and convert the analog signal into a digitalsignal for digital processing.

The signal processing can be performed directly on the time domainsignal received from a detector or the time domain signal received froma detector can be converted to the frequency domain for algorithmicprocessing. In FIG. 18, block 1830 converts sampled ECG waveform 1820 toa frequency domain signal. The time domain signal is converted into afrequency domain signal using a Fourier transform, for example.

As described above, through animal and/or human experimentation, thefrequency bands associated with different muscles of the heart can bedetermined. The frequency bands used here can be based on those bandsdetermined experimentally, for example. Alternatively, the 16 frequencybands can be found by dividing the total frequency bands 16 ways. Thedifferent band can have the same bandwidth or can have differentbandwidths.

In block 1840, 16 different band pass filters filter sampled ECGwaveform 1820's frequency domain signal into 16 different frequencydomain signal. These 16 different 16 different frequency domain signalsare then convert back to the time domain. The result of block 1840 is 16different time domain signals.

In block 1850, the 16 different time domain signals are combined orplotted together in the time domain as one multi-domain ECG waveform1860. In FIG. 1800, a conventional ECG signal from one electrode isprocessed into a multi-domain ECG waveform that includes 16 differenttime domain signals. In various embodiments, a conventional ECG signalfrom one electrode, however, can be processed into a multi-domain ECGwaveform that includes any number of different time domain signals.

FIG. 19 is an exemplary plot 1900 of a multi-domain ECG waveform thatincludes 10 different time domain signals, in accordance with variousembodiments.

FIG. 20 is an exemplary plot 2000 of a multi-domain ECG waveform thatincludes 14 different time domain signals, in accordance with variousembodiments.

FIG. 21 is an exemplary alignment 2100 of a multi-domain ECG waveform2110 that includes 16 different time domain signals with a conventionalECG waveform 2120, in accordance with various embodiments. Multi-domainECG waveform 2110 is produced from conventional ECG waveform 2120 usingthe system depicted in FIG. 18, for example. As shown in FIG. 21,multi-domain ECG waveform 2110 can display data with negative valueswhile conventional ECG waveform 2120 cannot.

In various embodiments, a multi-domain ECG waveform is generated foreach electrode.

FIG. 22 is an exemplary diagram 2200 showing portions of the threemulti-domain ECG waveform produced for three different ECG electrodes,I, II, and III, in accordance with various embodiments.

Converting a conventional ECG waveform into a multi-domain ECG waveformthat includes many different time domain signals can provide importantclinical information.

FIG. 23 is an exemplary alignment of multi-domain ECG waveforms measuredfor a patient with a 100% left anterior descending (LAD) artery and 80%right coronary artery (RAC) blockage before and after percutaneouscoronary intervention (PCI, formerly known as angioplasty with stent),in accordance with various embodiments. Multi-domain ECG waveform 2310was measured before PCI intervention. Multi-domain ECG waveform 2320 wasmeasured after PCI intervention. Both waveforms are measured from thesame electrode or lead (I). The differences in multi-domain ECGwaveforms 2310 and 2320 shows the clinical value of such waveforms. Inother words, multi-domain ECG waveforms can be used to diagnose specificconditions.

System for Detecting a Multi-Domain ECG Waveform

In various embodiments, an electrocardiography (ECG) system is providedfor detecting a multi-domain ECG waveform that includes two or moredifferent time domain signals that each represent a different frequencydomain signal. Returning to FIG. 8, the ECG system includes two or moreelectrodes 810, a detector 820, a signal processor 830, and a displaydevice 840.

Two or more electrodes 810 are placed proximate to a beating heart thatreceive electrical impulses from the beating heart. Two or moreelectrodes 810 are shown in FIG. 8 as noninvasive electrodes that areattached to the skin of a patient. In various embodiments, two or moreelectrodes 810 can be invasive electrodes placed directly on the surfaceof the heart or within heart tissue.

Detector 820 is electrically connected to two or more electrodes 810.Detector 820 detects the electrical impulses from at least one pair ofelectrodes of the two or more electrodes 810. Detector 820 converts theelectrical impulses to an ECG waveform for each heartbeat of the beatingheart. Detector 820, for example, samples the electrical impulses. Invarious embodiments, detector 820 further amplifies the ECG waveform. Invarious embodiments, detector 820 further performs analog to digital(A/D) conversion on the ECG waveform. In various embodiments, detector820 provides an ECG waveform with a higher signal-to-noise (S/N) ratiothan conventional ECG devices.

Signal processor 830 is electrically connected to detector 820. Signalprocessor receives the ECG waveform from detector 820. Signal processor830 converts the ECG waveform to a frequency domain waveform. Signalprocessor 830 separates the frequency domain waveform into two or moredifferent frequency domain waveforms using two or more differentbandpass filters. Finally, signal processor 830 converts the two or moredifferent frequency domain waveforms into two or more different timedomain waveforms.

Signal processor 830 separates the frequency domain waveform into two ormore different frequency domain waveforms by dividing the frequency bandof the ECG waveform into two or more different frequency bands andfiltering the two or more different frequency bands using the two ormore different bandpass filters, for example. In various embodiments,each of the two or more different frequency bands has the samebandwidth. In various alternative embodiments, each of the two or moredifferent frequency bands can have different bandwidths. In variousembodiments, the two or more different frequency bands are contiguousacross the frequency band of the ECG waveform. In various alternativeembodiments, the two or more different frequency bands are notcontiguous across the frequency band of the ECG waveform.

Signal processor 830 can be a separate device, can be software runningon device of detector 820 or display device 840, or can be softwarerunning on a remote server and communicating with detector 820 anddisplay device 840 through one or more communication devices. Signalprocessor 830 can be a separate device that includes, but is not limitedto, an application specific integrated circuit (ASIC) or a fieldprogrammable gate array (FPGA) or a general purpose processor. A generalpurpose processor can include, but is not limited to, a microprocessor,a micro controller, or a computer such as the system shown in FIG. 1.Signal processor 830 can be software implemented on another processor ofthe ECG device, such as a processor of display device 840. Signalprocessor 830 can also be a remote server that receives the detected andamplified difference voltage signal from detector 820.

Display device 840 displays the two or more different time domainwaveforms in the same time domain plot as a multi-domain ECG waveformfor the at least one heartbeat of the beating heart. As described above,display device 840 can be an electronic display device including, butnot limited to, a cathode ray tube (CRT) device, light emitting diode(LED) device, or Liquid crystal display (LCD) device. Display device 840can also be a printer device or any combination of an electronic displaydevice and a printer. Additionally, display device 840 can include amemory device to record saah ECG waveforms, saah ECG data andconventional ECG waveforms and data. The memory device can be, but isnot limited to, a volatile electronic memory, such as random accessmemory (RAM), a non-volatile electronic memory, such as electricallyerasable programmable read-only memory (EEPROM or Flash memory), or amagnetic hard drive.

In various embodiments, display device 840 further displays the ECGwaveform for at least one heartbeat of the beating heart. Display device840 further aligns the display of the multi-domain ECG waveform and thedisplay of ECG waveform in the time domain.

In various embodiments, display device 840 displays each time domainwaveform of the two or more different time domain waveforms in adifferent color. In various alternative embodiments, display device 840displays each time domain waveform of the two or more different timedomain waveforms in a different pattern of dashes.

Method for Detecting a Multi-Domain ECG Waveform

FIG. 24 is a flowchart showing a method 2400 for detecting amulti-domain ECG waveform that includes two or more different timedomain signals that each represent a different frequency domain signal,in accordance with various embodiments.

In step 2410 of method 2400, electrical impulses are detected between atleast one pair of electrodes of two or more electrodes placed proximateto a beating heart using a detector. The electrical impulses areconverted to an ECG waveform for each heartbeat of the beating heartusing the detector.

In step 2420, the ECG waveform for at least one heartbeat is receivedfrom the detector, the ECG waveform is converted to a frequency domainwaveform, the frequency domain waveform is separated into two or moredifferent frequency domain waveforms using two or more differentbandpass filters, and the two or more different frequency domainwaveforms are converted into two or more different time domain waveformsusing a signal processor.

In step 2430, the two or more different time domain waveforms aredisplayed in the same time domain plot as a multi-domain ECG waveformfor the at least one heartbeat of the beating heart using a displaydevice.

The foregoing disclosure of the preferred embodiments of the presentinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Many variations andmodifications of the embodiments described herein will be apparent toone of ordinary skill in the art in light of the above disclosure. Thescope of the invention is to be defined only by the claims appendedhereto, and by their equivalents.

Further, in describing representative embodiments of the presentinvention, the specification may have presented the method and/orprocess of the present invention as a particular sequence of steps.However, to the extent that the method or process does not rely on theparticular order of steps set forth herein, the method or process shouldnot be limited to the particular sequence of steps described. As one ofordinary skill in the art would appreciate, other sequences of steps maybe possible. Therefore, the particular order of the steps set forth inthe specification should not be construed as limitations on the claims.In addition, the claims directed to the method and/or process of thepresent invention should not be limited to the performance of theirsteps in the order written, and one skilled in the art can readilyappreciate that the sequences may be varied and still remain within thespirit and scope of the present invention.

What is claimed is:
 1. A noninvasive electrocardiography (ECG) systemfor detecting a multi-domain ECG waveform that includes two or moredifferent time domain signals that each represent a different frequencydomain signal, comprising: two or more electrodes attached to the skinof a patient near a beating heart of the patient that receive electricalimpulses from the beating heart; a detector that detects the electricalimpulses from at least one pair of electrodes of the two or moreelectrodes and converts the electrical impulses to an ECG waveform foreach heartbeat of the beating heart; a signal processor that receivesthe ECG waveform for at least one heartbeat from the detector, convertsthe ECG waveform to a frequency domain waveform, separates the frequencydomain waveform into two or more different frequency domain waveformsusing two or more different bandpass filters, and converts the two ormore different frequency domain waveforms into two or more differenttime domain waveforms; and a display device that displays the two ormore different time domain waveforms in the same time domain plot as amulti-domain ECG waveform for the at least one heartbeat of the beatingheart.
 2. The ECG system of claim 1, wherein the signal processorseparates the frequency domain waveform into two or more differentfrequency domain waveforms by dividing the frequency band of the ECGwaveform into two or more different frequency bands and filtering thetwo or more different frequency bands using the two or more differentbandpass filters.
 3. The ECG system of claim 2, wherein each of the twoor more different frequency bands has the same bandwidth.
 4. The ECGsystem of claim 2, wherein each of the two or more different frequencybands can have different bandwidths.
 5. The ECG system of claim 2,wherein the two or more different frequency bands are contiguous acrossthe frequency band of the ECG waveform.
 6. The ECG system of claim 2,wherein the two or more different frequency bands are not contiguousacross the frequency band of the ECG waveform.
 7. The ECG system ofclaim 1, wherein the display device further displays the ECG waveformfor at least one heartbeat of the beating heart.
 8. The ECG system ofclaim 7, wherein the display device further aligns the display of themulti-domain ECG waveform and the display of ECG waveform in the timedomain.
 9. The ECG system of claim 1, wherein the two or more differentfrequency domain waveforms comprise 16 different frequency domainwaveforms, and the two or more different time domain waveforms comprise16 different time domain waveforms.
 10. The ECG system of claim 1,wherein the display device displays each time domain waveform of the twoor more different time domain waveforms in a different color.
 11. TheECG system of claim 1, wherein the display device displays each timedomain waveform of the two or more different time domain waveforms in adifferent pattern of dashes.
 12. An invasive electrocardiography (ECG)system for detecting a multi-domain ECG waveform that includes two ormore different time domain signals that each represent a differentfrequency domain signal, comprising: two or more electrodes placeddirectly on a surface of a beating heart of a patient that receiveelectrical impulses from the beating heart; a detector that detects theelectrical impulses from at least one pair of electrodes of the two ormore electrodes and converts the electrical impulses to an ECG waveformfor each heartbeat of the beating heart; a signal processor thatreceives the ECG waveform for at least one heartbeat from the detector,converts the ECG waveform to a frequency domain waveform, separates thefrequency domain waveform into two or more different frequency domainwaveforms using two or more different bandpass filters, and converts thetwo or more different frequency domain waveforms into two or moredifferent time domain waveforms; and a display device that displays thetwo or more different time domain waveforms in the same time domain plotas a multi-domain ECG waveform for the at least one heartbeat of thebeating heart.
 13. The ECG system of claim 12, wherein the signalprocessor separates the frequency domain waveform into two or moredifferent frequency domain waveforms by dividing the frequency band ofthe ECG waveform into two or more different frequency bands.
 14. The ECGsystem of claim 13, wherein each of the two or more different frequencybands has the same bandwidth.
 15. The ECG system of claim 13, whereineach of the two or more different frequency bands can have differentbandwidths.
 16. The ECG system of claim 13, wherein the two or moredifferent frequency bands are contiguous across the frequency band ofthe ECG waveform.
 17. The ECG system of claim 13, wherein the two ormore different frequency bands are not contiguous across the frequencyband of the ECG waveform.
 18. The ECG system of claim 12, wherein thedisplay device further displays the ECG waveform for at least oneheartbeat of the beating heart.
 19. The ECG system of claim 18, whereinthe display device further aligns the display of the multi-domain ECGwaveform and the display of ECG waveform in the time domain.
 20. The ECGsystem of claim 12, wherein the two or more different frequency domainwaveforms comprise 16 different frequency domain waveforms, and the twoor more different time domain waveforms comprise 16 different timedomain waveforms.